Certain thiadiazolyl imidazolidinones

ABSTRACT

The invention discloses compounds of the formula   WHEREIN R1 is selected from the group consisting of alkyl of up to 3 carbon atoms, alkenyl, chloroalkyl, alkoxy, alkylthio, alkylsulfonyl and alkylsulfinyl; and R2 is alkyl.

United States Patent Krenzer CERTAIN THIADIAZOLYL IMIDAZOLIDINONES [75] Inventor: John Krenzer, Oak Park, Ill.

[73] Assignee: Velsicol Chemical Corporation,

Chicago, Ill.

[22] Filed: Feb. 11, 1974 [21] App]. No.: 441,682

Related US. Application Data [63] Continuation-impart of Ser. No. 388,005, Aug. 13,

1973, abandoned.

[52] US. Cl. 260/306.8 D; 71/90 [51] Int. Cl. C07D 417/04 [58] Field of Search 260/306.8 D

[56] References Cited UNITED STATES PATENTS 3,759,939 9/1973 Metzger et a] .Q 260/306.8 D

Primary Examiner-R. J. Gallagher Attorney, Agent, or FirmRobert J. Schwarz; Dietmar H. Olesch [57] ABSTRACT The invention discloses compounds of the formula N N CH CH 2 l n u I 2 R c c N N R S C ll 0 wherein R is selected from the group consisting of alkyl of up to 3 carbon atoms, alkenyl, chloroalkyl, alkoxy, alkylthio, alkylsulfonyl and alkylsulfinyl; and R is alkyl.

6 Claims, No Drawings CERTAIN THIADIAZOLYL IMIDAZOLIDINONES This application is a continuation in part of copending application Ser. No. 388,005, filed Aug. 13, 1973, now abandoned.

This invention relates to new compositions of matter and more particularly relates'to new chemical compounds of the formula wherein R is selected from the group consisting of alkyl of up to 3 carbon atoms, alkenyl, chloroalkyl, alkoxy, alkylthio, alkylsulfonyl and alkylsulfinyl; and R is alkyl.

The compounds of the present invention are unexpectedly useful as herbicides.

In a preferred embodiment of this invention R is selected from the group consisting of alkyl of up to 3 carbon atoms, lower alkenyl, lower chloroalkyl, lower alkoxy, lower alkylthio, lower alkylsulfonyl andlower al kylsulfinyl; and R is lower alkyl.

The term lower as used herein designates a straight or branched carbon chain of up to 6 carbon atoms.

The compounds of this invention can be readily prepared by heating a compound of the formula N N 1| II a l R C /C N C N CH CH I II I 1 2 H OCH S o R 3(II) wherein R and R are as heretofore described, in a dilute, aqueous, acidic reaction medium for a period of about 10 to about 60 minutes. Temperatures of from about 70C to the reflux temperature of the reaction mixture can be utilized. The reaction medium can comprise a dilute aqueous inorganic acid such as hydro- 'wherein R is as heretofore described, with about 2 molar amounts of a dimethyl acetal of the formula ?CH H N CH CH l 2 l R OCH (IV) wherein R is as heretofore described. This reaction can be effected by heating a mixture of the isocyanate dimerand the acetal in an inert organic reaction medium such as benzene at the reflux temperature of. the reaction mixture. Heating at reflux can be continued for a period of from about 2 to about 30 minutes to insure completionof the reaction. After this time the desired product can be recovered upon evaporation of the reaction medium and can be used as such or can be further purified by standard techniques in the art.

The isocyanate dimer of formula Ill can be prepared by reacting a thiadiazole of the formula wherein R is as heretofore described, with phosgene. This reaction can be effected by adding a slurry or solution of the thiadiazole, in a suitable organic solvent such as ethyl acetate, to a saturated solution of phosgene in an organic solvent such as ethyl acetate. The resulting mixture can be stirred at ambient temperatures for a period of from about 4 to about 24 hours. The reaction mixture can then be purged with nitrogen gas to remove unreacted phosgene. The desired product can then be recovered by filtration if formed as a precipitate or upon evaporation of the organic solvent used if soluble therein. This product can be used as such or can be further purified if desired. I v E Exemplary thiadiazoles of formula V useful for preparing the compounds of the present invention are 5- methyl-2-aminol ,3 ,4-thiadiazole, 5-ethyl-2-aminol ,3,4-thiadiazole, 5-propyl-2-aminol ,3,4-thiadiazole, 5-allyl-2-amino-1,3,4-thiadiazole, 5-pent-3-enyl-2- amino-l ,3,4-thiadiazole, 5-chloromethyl-2-amino- 1 ,3 ,4-thiadiazole, 5-B-chloro'ethyl-2-aminol ,3,4- thiadiazole, 5-'y chloropropyl-2-amino- 1 ,3 ,4- thiadiazole, 5-trichloromethyl-2-amino- 1 3 ,4- thiadiazole, 5-methoxy-2-aminol- ,3 ,4-thiadiazole, 5- ethoxy-Z-aminol ,3 ,4-thiadiazole, 5-propoxy-2-amino- 1 ,3,4-thiadiazole, 5-butyloxy-2-amino-l ,3,4- thiadiazole, S-hexyloxy-Zamino-1,3,4-thiadiazole, 5- methylthio-2-aminol ,3,4-thiadiazole, 5-ethylthio- 2aminol ,3,4-thiadiazole, 5 propylthio-Z-aminol ,3,4- thiadiazole, 5-butylthio-2-aminol ,3 ,4-thiadiazole, 5-

methylsulfonyl-Z-amino-l ,3 ,4-thiadiazole, 5- ethylsulfonyl-2-aminol ,3 ,4,-thiadiazole, 5- buty )sulfonyl-2-amino-l ,3,4-thiadiazole, 5- hexylsulfonyl-Z-aminol ,3,4-thiadiazole, 5- methylsulfinyl-Z-aminol ,3,4-thiadiazole, 5- ethylsulfinyl-2-amino-l 3 ,4-thiadiazole, 5

propylsulfinyl-Z-amino- 1 ,3,4-thiadiazole, 5-butylsulfinyl- 2-amino-l ,3,4-thiadiazole and the like.

The manner in which the compounds of the present invention can be prepared is more specifically illustrated in the following examples.

EXAMPLE 1 Preparation of S-Methyl-l,3,4-thiadiazol-2-yl I Isocyanate Dimer A saturated solution of phosgene in ethyl acetate (100 ml) is charged into a glass reaction vessel equipped with a mechanical stirrer. A slurry of methyl-2-amino-1,3,4-thiadiazole(40 grams) in ethyl acetate (300 ml) is added to the reaction vessel and the resulting mixture is stirred for a period of about 16 hours, resulting in the formation of a precipitate. The reaction mixture is then purged with nitrogen gas to remove unreacted phosgene. The purged mixture is then filtered to recover the precipitate. The precipitate is then recrystallized to yield the desired product S-methyll ,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 2 Preparation of the Dimethyl Acetal of 2-[ l-Methyl-3-( S-methyl- 1 ,3 ,4-thiadiazol-2- yl)ureido]acetaldehyde A mixture of S-methyl-l,3,4-thiadiazol-2-yl isocyanate dimer (0.05 mole), the dimethyl acetal of 2- methylaminoacetaldehyde (0.1 mole) and benzene (60 ml) are charged into a glass reaction vessel equipped with a mechanical stirrer and reflux condenser. The reaction mixture is heated at reflux for a period of about 15 minutes. After this time the mixture is stripped of benzene under reduced pressure to yield a solid product as the residue. The residue is then recrystallized to yield the desired product dimethyl acetal of 2-[1- methyl-3-( S-methyll ,3 ,4- thiadiaZol-2- yl )ureido acetaldehyde.

EXAMPLE 3 Preparation of l-( S-Methyl-l ,3 ,4-thiadiazol-2-yl )-3-methyl-5- hydroxy-l ,3-imidazolidin-2-one EXAMPLE 4 Preparation of S-Methoxy-1,3,4-thiadiazol-2-yl Isocyanate Dimer A saturated solution of phosgene in ethyl acetate (100 ml) is charged into a glass reaction vessel equipped with a mechanical stirrer. A slurry of 5- methoxy-2-amino-l,3,4-thiadiazole (40 grams) in ethyl acetate (300 ml) is added to the reaction vessel and the resulting mixture is stirred for a period of about 16 hours, resulting in the formation of a precipitate. The reaction mixture is then purged with nitrogen gas to remove unreacted phosgene. The purged mixture is then filtered to recover the precipitate. The precipitate is then recrystallized to yield the desired product 5- methoxy-1,3,4-thiadiazol2-yl isocyanate dimer.

EXAMPLE 5 Preparation of the Dimethyl Acetal of 2-[ l-Ethyl-3-( S-methoxyl ,3,4-thiadiazol-2- yl)ureido]acetaldehyde A mixture of S-methoxy-l,3,4-thiadiazol-2-yl isocyanate dimer (0.05 mole), the dimethyl acetal of 2- ethylaminoacetaldehyde (0.1 mole) and benzene ml) are charged into a flass reaction vessel equipped with a mechanical stirrer and reflux condenser. The reaction mixture is heated at reflux for a period of about 15 minutes. After this time the mixture is stripped of benzene under reduced pressure to yield the desired product the dimethyl acetal of 2-[ l-ethyl-3-(5- methoxy-l ,3 ,4-thiadiazol-2-y1)ureido ]acetaldehyde.

EXAMPLE 6 Preparation of l-(5-Methoxy- 1 ,3,4-thiadiazo1-2-yl)-3-ethyl-5- hydroxy-l ,3-imidazolidin-2-one The dimethyl acetal of 2-[ l-ethyl-3-(5-methoxyl,3,4-thiadiazo-2yl)ureido]acetaldehyde 15 grams), water (400 ml) and hydrochloric acid (4 ml) are charged into a glass reaction vessel equipped with a mechanical stirrer, thermometer and reflux condenser. The reaction mixture is heated at reflux for a period of about 15 minutes. The reaction mixture is then filtered while hot and the filtrate is cooled to form a precipitate. The precipitate is recovered by filtration, is dried and is recrystallized to yield the desired product l-(5- methoxy-l ,3 ,4-thiadiazol-2-yl )-3-ethyl-5-hydroxy-l ,3- imidazolidin-2-one.

EXAMPLE 7 Preparation of S-Methylthio-l,3,4-thiadiazol-2-yl lsocyanate Dimer EXAMPLE 8 Preparation of the Dimethyl Acetal of 2-[ 1-Propyl-3-(5-methylthio-1 ,3 ,4-thiadiazo1-2- yl)ureido]acetaldehyde A mixture of S-methylthio-l,3,4-thiadiazol-2-yl isocyanate dimer (0.05 mole), the dimethyl acetal of 2- propylaminoacetaldehyde (0.1 mole) and benzene (60 ml) are charged into a glass reaction vessel equipped with a mechanical stirrer and reflux condenser. The reaction mixture is heated at reflux for a period of about 15 minutes. After this time the mixture is stripped of benzene under reduced pressure to yield a solid product as the residue. The residue is then recrystallized to yield the desired product dimethyl acetal of 2-[1- propyl-3-( S-methylthio-l ,'3.4-thiadiazol2-yl ureidolacetaldehyde.

EXAMPLE 9 Preparation of l-( S-Methylthiol ,3 ,4-thiadiazol-2-yl )-3-propyl-5- hydroxy-l ,3-imidazolidin-2-one The dimethyl acetal of 2-[ l-propyl-3-(5-methylthiol,3,4thiadiazol-2-yl)ureido1acetaldehyde 15 grams) water (400 ml) and hydrochloric acid (4 ml) are charged into a glass reaction vessel equipped with a mechanical stirrer, thermometer and reflux condenser. The reaction mixture is heated at reflux for a period of about 15 minutes. The reaction mixture is then filtered while hot and the filtrate is cooled to form a precipitate. The precipitate is recovered by filtration, is dried and is recrystallized to yield the desired product l-(5- methylthiol ,3,4-thiadiazol-2-yl )-3-propyl-5-hydroxy- 1,3-imidazolidin-2-one.

EXAMPLE Preparation of S-Methylsulfonyll ,3,4-thiadiazol-2-yl lsocyanate Dimer EXAMPLE 1 1 Preparation of the-Dimethyl Acetal of 2-[ l-Methyl-3-( S-methylsulfonyll ,3 ,4-thiadiazol-2- yl)ureido]acetaldehyde EXAMPLE 12 Preparation of 1-( S-Methylsulfonyl-l ,3 ,4-thiadiazol-2-yl-3-rnethyl-5- hydroxy-l ,3-imidazolidin-2-one The dimethyl acetal of 2-[ l-methyl-3-(5- methylsulfonyll ,3 ,4-thiadiazol-2- yl)ureido]acetaldehyde (15 grams), water (400 ml.) and hydrochloric acid (4 ml) are charged into a glass reaction vessel equipped with a mechanical stirrer, thermometer and reflux condenser. The reaction mixture is heated at reflux for a period of about 15 minutes. The reaction mixture is then filtered while hot'and the filtrate is cooled to form a precipitate. The precipitateis recovered by filtration, is dried and is recrystallized to yield the desired product l-(S-methylsulfonylimidazolidin-Z-one.

EXAMPLE 13 Preparation of 5 Methylsulfinyll ,3,4-thiadiazol--2-yl lsocyanate Dimer 'Asaturated solution of phosgene in ethyl acetate ml) 'is charged into a glass reaction vessel equipped with a'mechanical stirrer. A slurry of 5- methylsulfin'yl-2- amino-l ,3,4-thiadiazole (50 grams) in ethyl acetate (300 ml) is added to the reaction 'vessel and the resulting mixture is stirred for a period of about 16 hours, resulting in the formation of a precipitate. The reaction mixture is then purged with nitrogen gas 'to remove unreacted phosgene. The purged mixture is then filtered to recover the precipitate. The precipitate is then recrystallized to yield the desired product 5- methylsulfinyl-l ,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE l4 7 Preparation of the Dimethyl Acetal of 2-[ l-Methyl-3-(S-methylsulfinyl-l ,3,4-thiadiazol-2- yl)ureido]acetaldehyde A mixture of,v 5l-rnethylsulfinyl-l ,3,4-thiadiazol-2-yl isocyanate dimer (0.05 mole), the dimethyl acetal of 2-methylaminoacetaldehyde (0.1 mole) and benzene (60 ml) are charged into a glass reaction vessel equipped with a mechanical ,stirrer and reflux condenser. The reaction mixture is heated at reflux for a period of about 1 5 minutes. After this time the mixture is stripped of benzene under reduced pressure to yield a solid product as the residue. The residue is then recrystallized to yield the desired product dimethyl acetal of 2 1-methyl-3-(S-methylsulfinyll ,3 ,4-thiadiazol-2- yl)-ureido]acetaldehyde.

' EXAMPLE l-5 r v v Preparation of i l-( S-Methylsulfinyll ,3,4-thiadiazol-2-yl)-3-methyl-5- hydroxy- 1 ,3-imidazolidin-2-one The dimethyl acetal of methylsulfinyl-l ,3,4-thiadiazol-2- yl)ureido]acetaldehyde .(15 grams), water (400 ml) and hydrochloric acid (4 ml) are charged into a glass reaction vessel equipped with a mechanical stirrer, thermometer andreflux condenser. The reaction mixture is heated 1at .reflux for a period of about 15 minutes. The reaction mixture is then filtered while hot and the filtrate is cooled toform a precipitate. The precipitate is recovered by filtration, is dried and is recrystallized to yield the desired product l-(5-methylsulfinyll ,3 ,4- thiadiazol-, 2-yl)-3-methyl-5-hydroxyl ,3- imidazolidin-Z-one. Y

Additional compounds within the scopeof the present invention which can be prepared bythe procedures of the foregoing examples are l-(5-.ethyl-l,3,4-

thiadiazol-Z-yl)-3-butyl-5-hydroxy-'l ,3-imidazolidin- 2one, l-( S-propyl-l ,3 ,4-thiadiazol-2-yl )-3-pentyl-5 hydroxyl ,3-imidazolid in-2-one, l-( S-butylthio-l 3 ,4- thiadiazol-2-yl )-3-hexyl-5 -hydroxyl ,3-imidazolidin- 2-one l-( 5.-pentylthiol ,3 ,4-thiadiazol-2-yl )-3-methyl- S-hydroxyl -,3 -imidaezolidin-2-one, l-( S-hexylthiol ,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxyl ,3- imidazolidin-Z-one, l-( S-ethylthiol ,3 ,4-thiadiazol-2- yl)-3-methyl-5-hydroxyl ,3-imidazolidin-2-one, l-( ethoxy-l ,3 ,4-thiadiazol-2-yl )-3-methyl-5-hydroxy-l ,3- imidazolidin-Z-one, l-( 5-propoxyl ,3,4-thiadiazol-2- yl )-3-methyl-5-hydroxy-l ,3-imidazolidin-2-one, l-( 5- butoxy-l ,3,4-thiadiazol-2-yl) 3-methyl-S-hydroxy-1 ,3- imidazolidin-2-one, l-( 5-hexyloxy-l ,3 ,4-thiadiazol-2- yl)-3-methyl-5-'hydroxy-l ,3-imidazolidin-2-one, l-( 5- chloromethyll ,3 ,4-thiadiazol-2-yl )-3-methyl-5- hydroxyl ,3-imidazolidin-2-one, l-( S-B-chloroethyl- 1,3 ,4-thiadiazol-2-yl)-3-methyl-5-hydroxyl ,3- imidazolidin-Z-one, l-(5-y-chlorobutyl-chl orobutyl- 1,3 ,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1 ,3- imidazolidin-2-one, l-( 5-allyl- 1 ,3,4-thiadiazol-2 yl )-3- methyl-S-hydroxy-1,3-imidazolidin-2-one, l-(5-pent-3- enyl-l ,3,4-thiadiazol 2-yl)-3-methyl-5-hydroxy-1,3- imidazolidin-Z-one, l-(5-hex-5-enyl-1,3,4-thiadiazol-2- yl )-3-methyl-5-hydroxy-l ,3-imidazolidin-2-one, l-( 5- ethylsulfonyl?1 ,3,4-thiadiazol-2-yl)-3-methyl-5- hydroxy-l ,3-imidazolidin-2-one, l-(S-propylsulfonyl- 1,3 ,4 thiadiazol-2-yl)-3-methyl-5-hydroxyl ,3- imidazolidin-Z-one, l-(5-butylsulfonyl-1,3,4- thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin- 2 -one, l-(5-hexylsulfonyll,3,4-thiadiazol-2-yl')-3- methyl-S-hydroxy-l ,3-imidazolidin-2-one, l-( 5- ethylsulfinyll ,3,4-thiadiazol-2-yl )-3-methyl-5- hydroxy-l ,3-imidazolidin-2-one, l-( 5-propylsulfinyll,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxyl ,3- imidazolidin-2-one, l-(5-butylsulfinyll ,3,4-thiadiazol- 2-yl )-3-methyl-5-hydroxyl ,3-imidazolidin-2-one, l- (S-pentylsulfinyll ,3,4-thiadiazol-2-yl )-3-methyl-5- hydroxy-l ,3-imidazolidin-2-one, l-( S-hexylsulfinyll ,3 ,4-thiadiazol-2-yl )-3-methyl-5-hydroxyl ,3- imidazolidin-Z-one.

\ For practical use as herbicides the compounds of this invention are generally incorporated into herbicidal compositions which comprise an inert carrier and a herbicidally toxic amount of such a compound. Such herbicidal compositions, which can also be called formulations, enable the active compound to be applied conveniently to the site of the weed infestation in any desired quantity. These compositions can be solids such as dusts, granules, or Wettable powders; or they can be liquids such as solutions, aerosols, or emulsifiable concentrates. vermiculites,

For example, dusts can be prepared by grinding and blending the active compound with a solid inert carrier such as' the tales, clays, silicas, pyrophyllite, and the like; Granular formulations can be prepared by impreg- I nating the compound, usually dissolved in a suitable solvent, onto and into granulated carriers such as the attapulgites or the vermiculities, usually of a particle size range of from about 0.3 to 1.5 mm. Wettable powders, which can be dispersed in water or oil to any desired concentration of the active compound, can be prepared by incorporating wetting agents into concentrated dust compositions.

In some cases the-active compounds are sufficiently soluble in common organic solvents such as kerosene or xylene so that they can be used directly as solutions in these solvents. Frequently, solutions of herbicides can be dispersed under super-atmospheric pressure as aerosols. However, preferred liquid herbicidal compositions are emulsifiable concentrates, which comprise an active compound according to this invention and as the' inert carrier, a solvent and an emulsifier. Such emulsifiable concentrates can be extended with water and/or oil to any desired concentration of active com- EXAMPLE 1 6 Preparation of a Dust Product of Example 3 Powdered Talc The above ingredients are mixed in a mechanical grinder-blender and are ground until a homogeneous, free-flowing dust of the desired particle size is obtained. This dust is suitable for direct application to the site of the weed infestation.

The compounds of this invention can be applied as herbicides in any manner recognized by the art. One method for the control of weeds comprises contacting the locus of said weeds with a herbicidal composition comprising an inert carrier and as an essential active ingredient, in aquantity which is herbicidally toxic to said weeds, a compound of the present invention. The concentration of the new compounds of this invention in the herbicidal compositions will vary greatly with the type of formulation and the purpose for which it is designed, but generally the herbicidal compositions will comprise from about 0.05 to about percent by weight of the active compounds of thisinvention. In a preferred embodiment of thisinvention, the herbicidal compositions will comprise from about 5 to about 75 percent by weight of the active compoundQThe compositions can also comprise such additionalsubstances as other pesticides, such as insecticides, nematocides, fungicides, and the like; stabilizers, spreaders, deactivators, adhesives, stickers, fertilizers, activators, synergists, and the like.

The compounds of the present invention are also useful when combined with other herbicides and/or defoliants, dessicants, growth inhibitors and the like in the herbicidal compositions heretofore described. These other materials can comprise from about 5'to about 95 percent of the active ingredients in the herbicidal compositions. Use of combinations of these other herbicides and/or defoliants, dessicants, etc. with the compounds of the present invention provide herbicidal compositions which are more effective in controlling weeds and often provide results unattainable with separate compositions of the individual herbicides. The other herbicides, defoliants, dessicants and plant growth inhibitors, with which the compounds of this invention can be used in the herbicidal compositions to control weeds, can include chlorophenoxy herbicides such as 2,4-D, 2,4,5-T, MCPA, MCPB, 4(2,4-DB), 2,4- DEB,-4-CPB, 4-CPA, 4-CPP, 2,4,5-TB, 2,4,5-TES, 3,4- DA, silvex and the like; carbamate herbicides such as IPC, CIPC, swep, barban, BCPC, CEPC, CPPC, and the like; thiocarbamate and dithiocarbamate herbicides such as CDEC, metham sodium, EPTC, diallate, PEBC, perbulate, vernolate the the like; substituted urea herbicides such as norea, siduron, dichloral urea, chloroxuron, cycluron, fenuron, monuron, monuron TCA, diuron, linuron, monolinuron, neburon, buturon, trimeturon and the like; symmetrical triazine herbicides such as simazine, chlorazine, atraone, desmetryne, norazine, ipazine, prometryn, atazine, trietaz ine, simetone, prometone, propazine, ametryne and the like; chloroacetamide herbicides such as alpha-chloro-N, N- dimethylacetamide, CDEA, CDAA, alpha-chloro-N- isopropylacetamide, 2-chloro-N-isopropylacetanilide, 4-( chloroacetyl )morpholine, l-( chloroacetyl) piperidine, and the like; chlorinated aliphatic acid herbicides such as TCA, dalapon, 2,3-dichloropropionic acid, 2,2,3-TPA and the like; chlorinated benzoic acid and phenylacetic acid herbicides such as 2,3,6-TBA, 2,3,5,6-TBA, tricamba, amiben, fenac, methoxy-3,6-dichlorophenylacetic acid, 3-methoxy- 2,6-dichlorophenylacetic acid, 2-methoxy-3,5,6-trichlorophenylacetic acid, 2,4-dichloro3-nitrobenzoic acid and the like; and such compounds as aminotriazole, maleic hydrazide, phenyl mercuric acetate, endothal, biuret, technical chlordane, dimethyl 2,3,5,6- tetrachloroterephthalate, diquat, erbon, DNC, DNBP, dichlobenil, DPA, diphenamid, dipropalin, trifluralin, solan, dicryl, merphos, DMPA, DSMA, MSMA, Potassium azide, acrolein, benefin, bensulide, AMS, bromacil 2( 3 ,4-dichlorophenyl )-4-methyl-1 ,2,4- oxadiazolidine-3,5-dione, bromoxynil, cacodylic acid, CMA, CPMF, cypromid, DCB, DCPA, dichlone, diphenatril, DMTT, DNAP, EBEP, EXD, HCA, ioxynil, IPX, isocil, potassium cyanate, MAA, MAMA, MCPES, MCPP, MH, molinate, NPA, OCH, paraquat, PCP, picloram, DPA, PCA, pyrichlor, sesone, terbacil, terbutol, TCBA, brominil, CI -50144, H-l'76-l, H-732, M-290l planavin, sodium tetraborate, calcium cyanamid, DEF, ethyl xanthogen disulfide, sindone, sindone B, propanil and the like.

Such herbicides can also be used in the methods and compositions of this invention in the form of their salts, esters, amides, and other derivatives whenever applicable to the particular parent compounds.

Weeds are undesirable plants growing where they are not wanted, having no economic value, and interfering with the production of cultivated crops, with the growing of ornamental plants, or with the welfare of livestock. Many types of weeds are known, including annuals such as pigweed, lambsquarters, foxtail, crabgrass, wild mustard, field pennycress, ryegrass, goose-grass, chickweed, wild oats, velvetleaf, purslane, barnyard grass, smartweed, knotweed, cocklebur, wild buckwheat, kochia, medic, corn cockle, ragweed, sowthistle, coffeeweed, croton, cuphea, dodder, fumitory, groundsel, hemp nettle, knawel, spurge, spurry, emex, jungle rice, pondweed, dog fennel, carpetweed, morning glory, bedstraw, ducksalad, naiad, cheatgrass, fall panicum, jimsonweed, witchgrass, switchgrass, watergrass, teaweed, wild turnip and sprangletop; biennials such as wild carrot, matricaria, wild barley, campion, chamomile, burdock, mullein, roundleaved mallow, bull thistle, hounds-tongue, moth mullein and purple star thistle; or perennials such as white cockle, perennial ryegrass, quackgrass, Johnson grass, Canada thistle, hedge bindweed, Bermuda grass, sheet sorrel, curly dock, nutgrass, field chickweed, dandelion, campanula, field bindweed, Russian knapweed, mesquite, toadflax, yarrow, aster, gromwell, horsetail, ironweed, sesbania, bulrush, cattail, winter-Cress, horsenettle, nutsedge, milkweed and sicklepod.

PBA, 2-

Similarly, such weeds can be classified asbroad-leaf o'i' grassy weeds. It is economically desirable to control the growth of such weeds without damaging beneficial plants or livestock. v i

The new compounds of this invention are particularly valuable for'weed control because they are toxic to many species and groups of weeds while they are relatively non-toxic to many beneficial plants. Theexact amount of compound required will depend onja variety of factors, including the hardiness of particular weed species, weather, type of soil, method of application, the kind of beneficial plants in the same area, and the like. Thus, while the application of up to only about one or two ounces of active compound per acre may be sufficient for good control of a light infestation of weeds growing under adverse conditions, the application of ten pounds or more of an active compound per acre may be required for good control of a dense infestation of hardy perennial weeds growing under favorable conditions.

The herbicidal toxicity of the new compounds of this invention can be illustrated by many of the established testing techniques known to the art, such as preand post-emergence testing.

The herbicidal activity of the compounds of this invention can be demonstrated by experiments carried out for the pre-emergence control of a variety of weeds. In these experiments small plastic greenhouse pots filled with dry soil are seeded with the various weed seeds. Twenty-four hours or less after seeding the pots are sprayed with water until the soil is wet and the test compounds formulated as aqueous emulsions of acetone solutions containing emulsifiers are sprayed at the indicated concentrations on the surface of the soil.

After spraying, the soil containers are placed in the greenhouse and provided with supplementary heat as required and daily or more frequent watering. The plants are maintained under these conditions fora period of from 15 to 21 days, at which time the condition of the plants and the degree of injury of the plants can be observed. 7

The herbicidal activity of the compounds of this invention can also be demonstrated by experiments carried out for the post-emergence control of a variety of weeds. In these experiments the compounds to be tested are formulated as aqueous emulsions and sprayed at the indicated dosage on the foliage of the weeds that have attained a prescribed size. After spraying the plants are placed ina greenhouse and watereddaily or more frequently. Water is not applied to the foliage of the treated plants. The severity of the injury is determined l0 to 15 days after treatment.

I claim:

l. A compound of the formula 11 N N CHCH2 ,II n: I Rrc C-N N- wherein R} is selected from the group consisting of 4. The compound of claim 1, l-(5-methylthio-l,3,4- thiadiazol-Z-yl)-3-propyl-5-hydroxy-1,3-imidazolidin- 2-one.

5. The compound of claim 1, l-(S-methylsulfonyll ,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3- imidazolidiri-Z-one.

6. The compound of claim 1, l-(5-methylsulfinyll ,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxyl ,3-

imidazolidin-2-one. V

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,901,904

DATED August 26, 1975 INVENTORG/ John Krenzer It is certified that error appears in the ab0ve-ideritified patent and that said Letters Patent are hereby corrected as shown below:

column 2, line 63, for "buty)sulfonyl2aminol,3,4

thiadiazole," read butylsulfonyl-2-amino-l,3,4- thiadiazole,

column 4, line 12, for "flass" read glass column 5, line 57, for "l-(5Methylsulfonyll,3,4-thiadiazol- 2yl3methyl5-" read l-(5Methylsulfonyll,3,4 thiadiazol-Z-yl)3methyl-5 column 6, line 61, for "Zone," read 2-one,

column 7, line ll, for "l- (5Ychlorobutyl-chlorobutyl-" read l- (5-Y-chlorobutylcolumn 7, line 44, delete "vermiculites,".

column 11, line 3, for "alkylthis" read alkylthio Signed and Sealed this third Day Of February 1976 [SEAL] A ttest:

RUTH C. MASON Arresting Officer UNITED STATES PATENT OFFICE CERTIFICATE OF CQRRECTIN Patent NO. 5,901,90h Dated August 1975 Inventor(s) John Krenzer It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

The term of this patent subsequent to August 26, 1992 has been disclaimed.

. Signed and Scaled this Thirteenth Day Of July 1976 [SEAL] A ttest:

RUTH c. m sou c. MARSHALL DANN Arte-"m3 Office Commissioner of Parents and Trademarks 

1. A COMPOUND OF THE FORMULA
 2. The compound of claim 1, 1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2 -one.
 3. The compound of claim 1, 1-(5-methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl-5-hydroxy-1,3-imidazolidin-2 -one.
 4. The compound of claim 1, 1-(5-methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-hydroxy-1,3-imidazolidin-2-one.
 5. The compound of claim 1, 1-(5-methylsulfonyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3 -imidazolidin-2-one.
 6. The compound of claim 1, 1-(5-methylsulfinyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3 -imidazolidin-2-one. 